This invention relates to a novel improvement in the structure of conventional transparent heat ray (infrared) reflecting glass with high heat insulation, high luminosity and monodirectional reflection while eliminating the duplicated virtual images or distorted static image often seen on the inner surface of conventional heat ray reflecting glass. Conventional heat ray reflecting laminated safety glass, widely used for the curtain walls of buildings, are made by using strong adhesives to laminate together two sheets of plate glass substrate having a desired thickness into a laminate structure wherein on the inner surface of the first outward-facing transparent or colored plate glass substrate is reflective film-treated, plated or coated with a metal or metallic oxide heat ray reflecting layer by conventional methods such as vacuum deposition, electroless plating or thermal decomposition, oxidization and the other second plate may be polyester or polycarbonate plate depending upon the particular applications.
The reflecting rate of conventional metal or metallic oxide reflecting film coated on the inner surface of the aforesaid outer plate glass substrate is generally about 12% to 50%, and the polymeric resin laminating adhesive layer in-between the two substrates is about 0.01 to 3 m/m in thickness, so the glass of curtain walls become mirror-like when viewed from the outside of the building. However, since the glass sheet and resin adhesive layer possess different reflecting rates of 1.52 and 1.48 to 1.6 respectively, a daze or visual compression will usually arise from the duplicated virtual image or distorted static image brought out by the discrepancy of reflective indices among materials of different densities and the uneven surface of glass sheets when produced. This phenomenon will especially deteriorate further when outdoors is brighter than indoors or the intermediate adhesive layer is thicker. Such adverse on the human eye have in the past been relieved only by using dark-colored heat-absorbing glass for the inner plate glass substrate to reduce or cover indoor images on the reflecting film or the dazzling lights; another words, there is not yet another effective means for overcoming or solving such disadvantages as the above-mentioned duplicated virtual image on conventional heat ray reflecting laminated safety glass.
Currently the transparency rate is maintained within the range of 40% to 8% for interior lighting while the heat ray reflecting rate is within the range from 12% to 50%. Accordingly, in addition to aforementioned disadvantages, the transparency rate for luminosity decreases as the reflecting rate of the metal or metallic oxide layer is increased to more than 50% even though more energy for air conditioning is saved as a result of fewer solar rays passing through. It therefore, becomes a most critical issue for those skilled in the art to find a way to obtain a more satisfactory reflecting rate as well as a transparency rate that are indirectly proportional to each other.